This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Attention to asbestos-related diseases has re-emerged due to the exposure of Libby, Montana residents to asbestos-contaminated vermiculite. Vermiculite distribution to over 200 sites nationwide and the long latent period for disease development make asbestos-related diseases a continuing public health issue. Previous studies demonstrated increased expression of Sparc and Adam28 in asbestos-exposed mouse lungs, including those exposed to the Libby amphibole. Both Sparc and Adam 28 encode proteins involved in the regulation of extracellular matrix (ECM) [unreadable] cell interactions, including the tissue remodeling similar to that occurring during fibrosis. The functions of these proteins make them exciting candidates for involvement in the fibrosis that occurs after asbestos exposure. Our hypothesis is that expression of the proteins encoded by Sparc and Adam28 are significant steps in the development of lung fibrosis after asbestos exposure. To test the hypothesis, the specific aims will 1) establish the in vivo gene and protein expression of Sparc and Adam28 in Sparc-null and matched wild-type mice after exposure to saline, the Libby amphibole, and crocidolite asbestos and 2) determine the response of primary lung fibroblast cultures isolated from the Sparc-null and matched wild-type mice to the same three treatments by examining ECM production. The proposed studies will enhance understanding of the interaction between cells and ECM in response to the Libby amphibole. With health risks faced by thousands of exposed individuals, the ultimate goal of these studies is to identify novel therapeutic targets for these and other similar lung diseases.